Navegando por Palavras-chave "Radiation Injuries"

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    Effects of ionizing radiation on bone neoformation: histometric study in Wistar rats tibiae
    (Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia, 2011-12-01) Lucatto, Susette Cavicchioli [UNIFESP]; Guilherme, Arnaldo [UNIFESP]; Dib, Luciano Lauria [UNIFESP]; Segreto, Helena Regina Comodo [UNIFESP]; Alves, Maria Teresa de Seixas [UNIFESP]; Gumieiro, Emne Hammoud [UNIFESP]; Jahn, Ricardo Schmitutz [UNIFESP]; Leite, Ronaldo Antonio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Paulista University Faculty of Dentistry Department of Stomatology
    PURPOSE: Comparing the ionizing radiation effects on bone neoformation of rats tibiae previously submitted to radiotherapy with a single dosage of 30Gy with the contralateral tibiae that have received secondary radiation. METHODS: In thirty male Wistar rats, 30 days before surgical procedure when round defects would be created on the bone, the right tibia was irradiated with 30Gy and the left tibia received a calculated secondary radiation dose of 7Gy. Sacrifices were performed after 4, 7, 14, 21, 56 and 84 postoperative days and both tibiae were removed for histological processing. RESULTS: The left tibiae that received the dose of 7Gy has shown more bone neoformation from 14th postoperative days, giving evidences of less damage to cellular population responsible by bone neoformation. On the other hand, the dose of 30Gyon right tibiae did not exhibit significant differences among the periods, suggesting damage of long-lasting or even permanent duration. CONCLUSION: Tibiae submitted to radiation dose of 30Gy have shown more damage to bone cells than tibiae that received secondary radiation dose of 7Gy, especially observed on 14th, 56th and 84th postoperative days.
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    Experimental model of cutaneous radiation injury in rabbits
    (Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia, 2013-11-01) Meirelles, Rafael Panisi de Campos [UNIFESP]; Hochman, Bernardo [UNIFESP]; Helene Junior, Americo; Lellis, Rute; Fraga, Murillo Francisco Pires; Ferreira, Lydia Masako [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Department of Surgery Division of Plastic Surgery; Faculty of Medical Sciences of Santa Casa of São Paulo Department of Surgery Division of Plastic Surgery; Faculty of Medical Sciences of Santa Casa of São Paulo Division of Plastic Surgery
    PURPOSE: To describe an experimental model of cutaneous radiation injury in rabbits. METHODS: On this study eight six-month-old New Zealand male rabbits, with an average weight of 2.5kg were used. They were distributed in four groups (n=2 per group). The control group did not receive radiotherapy and the others received one radiotherapy session of 2000, 3000 and 4500 cGy, respectively. Photographic analysis and histopathological evaluation of the irradiated areas were carried out. RESULTS: After 30 days, the animals from the control group had all their hair grown. In spite of that, the animals from group 2000 cGy had a 60-day alopecia and from group 3000 cGy, a 90-day alopecia. After the 30th day, the 3000cGy group demonstrated 90-day cutaneous radiation injuries, graded 3 and 4. One of the animals from group 4500 cGy died on the 7th day with visceral necrosis. The other from the same group had total skin necrosis. A progressive reduction of glands and blood vessels count and an increase on collagen deposition was observed. CONCLUSION: The proposed experimental model is reproductable. This study suggests that the dosage 4500cGy is excessive and the 3000 cGy is the most effective for this experimental model of cutaneous radiation injury in rabbits.